Moved some std includes out from catch_common.h
diff --git a/include/internal/catch_test_case_info.hpp b/include/internal/catch_test_case_info.hpp
index abba5d9..b4ca53a 100644
--- a/include/internal/catch_test_case_info.hpp
+++ b/include/internal/catch_test_case_info.hpp
@@ -13,6 +13,8 @@
 #include "catch_interfaces_testcase.h"
 #include "catch_common.h"
 
+#include <cctype>
+
 namespace Catch {
 
     inline TestCaseInfo::SpecialProperties parseSpecialTag( std::string const& tag ) {